Include the native javascript react and react_dom libraries (provided with this library for compatibility reasons) in index.html and create element where you'll mount the react component you'll create.

If you are familiar with React (without JSX extension) React-dart shouldn't surprise you much. All elements are defined as
functions that take props as first argument and children as optional second argument. props should implement Map and children is either one React element or List with multiple elements.

Proper usage of refs here is a little bit different from usage in react. You can specify
a ref name in component props and then call ref method to get the referenced element.
Return values for Dart components, DOM components and JavaScript components are different.
For a Dart component, you get an instance of the Dart class of the component.
For primitive components (like DOM elements), you get the DOM node. For JavaScript composite components,
you get a ReactElement representing the react component.

If you want to work with DOM nodes of dart or JS components instead, you can call top level method findDOMNode on anything the ref returns.